1. Technical Field
The present invention relates to a disc reproducing apparatus in which a plurality of discs are set onto a rotary table, and a tray can be discharged during a reproduction process to enable a disc to be exchanged with another one, and more particularly to a disc reproducing apparatus in which, when a tray is moved to a discharging position or a accommodating position during a process of reproducing a disc, a trouble such as a track jump is prevented from accidentally occurring.
2. Related Art
In a disc reproducing apparatus having a so-called carrousel type exchanger, a rotary table is disposed on a tray which can be moved to a discharging position and an accommodating position. A plurality of discs can be set onto the rotary table, and a reproduction operation is performed on one of the discs which are set onto the rotary table. The tray can be moved also when a disc is being reproduced. When the tray is moved during a process of reproducing a disc, therefore, a shock during the movement may cause a read error or a track jump on the reproduced disc to occur. Consequently, a technique for preventing such a trouble from occurring is proposed in the Japanese Utility Model Publication No. Hei7-22758.
In the proposed technique, the output of a focus control circuit is amplified, the outputs of a drive circuit for driving a focus coil and a tracking control circuit are amplified, and the gain of a drive circuit for driving a tracking coil is made variable. When an operation of discharging or accommodating a tray is detected, i.e., when movement of the tray is detected, a system controller increases the gains of the focusing drive circuit and the tracking drive circuit. As a result, when the tray is moved, the loop gains in the focus control and the tracking control are increased. Even when a shock due to movement of the tray is produced, therefore, the focus control and the tracking control are prevented from unexpectedly failing, thereby preventing a track jump or a read error from accidentally occurring.
Even in the case where the above-mentioned configuration is used, however, the following problem arises. Even in the case where the loop gains in the focus control and the tracking control are increased, when the moving speed of the tray is set to be higher, a large shock due to movement of the tray is produced, so that a track jump or a read error accidentally occurs. Therefore, the moving speed of the tray cannot be set to a very high level. As a result, when a disc on the rotary table is to be exchanged with another one, the user feels that the time period required for moving the tray in the accommodating position to the discharging position, and that required for moving the tray in the discharging position to the accommodating position are long, and hence the operability is poor.
The invention has been conducted in order to solve the problem. It is an object of the invention to provide a disc reproducing apparatus in which, when a reproduction operation is performed on a disc, a tray is moved at a speed that is lower than that at which the tray is moved when a reproduction operation is not performed, whereby, even when poor operability that the moving speed of the tray is low is to be improved, a track jump and a read error are prevented from accidentally occurring.
In addition to the object, it is a further object of the invention to provide a disc reproducing apparatus in which, when the tray approaches the discharging position or the accommodating position, the speed of moving the tray is lowered, whereby, even when a track jump and a read error are prevented from accidentally occurring, the time period required for moving the tray can be shortened.
In addition to the object, it is a still further object of the invention to provide a disc reproducing apparatus in which, when an FG signal indicates that a disc motor is rotating, it is judged that a reproduction operation is being performed, whereby the work of modifying an apparatus in which the speed of moving the tray in the case where the reproduction operation is performed is identical with that in the case where the reproduction operation is not performed, to an apparatus in which the speed of moving the tray in the case where the reproduction operation is performed is different from that in the case where the reproduction operation is not performed can be minimized.
In order to solve the problem, the invention is applied to a disc reproducing apparatus comprising: a tray which is movably disposed in an apparatus body; tray driving means for moving the tray to an accommodating position and a discharging position; a rotary table which is rotatably attached to the tray, and in which a plurality of disc holding portions are formed around a rotation shaft; and disc reproducing means, disposed separately from the tray, for, when the tray is in the accommodating position, clamping a disc which is held by one of the disc holding portions, and reproducing the clamped disc, both when the disc reproducing means is performing a reproduction operation on a disc, and when the disc reproducing means is not performing a reproduction operation on a disc, the tray being movable to the accommodating position and the discharging position. When the disc reproducing means is performing a reproduction operation on a disc, the tray driving means moves the tray at a speed that is lower than a speed at which, when the disc reproducing means is not performing a reproduction operation on a disc, the tray driving means moves the tray.
When the disc reproducing means is not performing a reproduction operation on a disc, the tray is moved at a high speed. Therefore, the time period required for moving the tray is short, and comfortable operability is attained. When the disc reproducing means is performing a reproduction operation on a disc, the tray is moved at a low speed. Therefore, a shock and vibrations which are produced by movement of the tray is suppressed. In the disc reproducing means, consequently, a read error and a tracking failure do not occur.
In addition to the above-mentioned configuration, when the tray approaches the discharging position or the accommodating position, the tray driving means lowers the speed at which the tray driving means moves the tray.
Namely, the time period required for moving the tray is prevented from being prolonged, and a shock which is produced when the tray is stopped is suppressed.
The invention is applied to a disc reproducing apparatus in which, in addition to the above-mentioned configuration, FG signal generating means for generating an FG signal is disposed in a disc motor for rotating a disc, and the tray driving means judges whether a disc is being reproduced or not, on the basis of an output of the FG signal generating means.
Namely, the configuration can be changed to that in which the speed of moving the tray when a reproduction operation is performed is lower than that when a reproduction operation is not performed, simply by conducting a change of supplying the FG signal to the tray driving means and modifying the tray driving means.